Members stomias Posted April 22, 2011 Members Posted April 22, 2011 Really liked this....mathematics and lesbians http://www.lydiandominant.com/theory/lydian-dominant_theory.html
Members polishpaul Posted April 22, 2011 Members Posted April 22, 2011 Sparse, lesbianally, but rich in information, musically. This could take a while......thanks.
Members polishpaul Posted April 22, 2011 Members Posted April 22, 2011 Worth reading, because it goes into this:Experiments on strings by ancient people showed that when you take a string tuned to any starting pitch and divide it into 2's you get octave doublings. When you divide it into 3's, you get what is known as a perfect 5th. When you divide it into 5's, you get what is known as a Major 3rd. When you divide it into 7's, you get what is known as a Minor 7th. I think all musicians should know this stuff......................like mechanics know where petrol comes from. Not essential knowledge, but useful in the big picture.......scheme of things.......other idioms............
Members polishpaul Posted April 22, 2011 Members Posted April 22, 2011 to much math for me I know how you feel.......but I reckon it's worth plodding through stuff like this. Having burnt out plenty of brain cells in this pursuit, I've reached the point where I can play the expected dominant seventh, or try out its substitution to see how it sounds without really having to think much at all. Try this: Dm7 G7 Cmaj7.......... ....which is okay......... ....but not as cool as: Dm7 Db7 Cmaj7. The latter gives you a smooth descending chromatic bass line.....D-Db-C.....which you don't get in the former. Works in all keys! Learn one, get eleven free !
Members JonR Posted April 23, 2011 Members Posted April 23, 2011 Several errors in that link. If not errors, then fuzzy thinking, or non sequiturs. (Sounds like someone too easily persuaded by apparent mathematical aspects of music...) The math is correct, but it doesn't apply to lydian dominant the way he is implying. He says (correctly) that in our 12-tone equal tempered (12-TET) system, the 5ths are flattened by 2 cents to remove what he calls the "Pythagorean Error Factor" (and which the rest of us know as the "Pythagorean comma") and make the circle of 5ths close. However, this means the lydian dominant scale (on a 12-TET instrument) no longer matches the overtones of the root. The b7 is 33 cents (1/3 of a half-step) sharp of the corresponding harmonic; the #11 is around 50 cents sharp of the harmonic (so the harmonic is exactly in between the perfect 11th and #11); and the 13th is also sharp of the harmonic (again, the harmonic is in between b13 and 13). So much for the "naturalness" of lydian dominant... I don't know which "ancient people" he means who divided strings into 5 or 7. Pythagoras only went as far as 2 and 3, and whole scale systems can be (and were) built on those factors. It was only later (some time in the middle ages) that the factor of 5 came into play, to define a "pure" major 3rd. The pythagorean 3rd is 81:64 (not 5:4), which many feel is uncomfortably sharp; 5:4 is a much more "natural" ratio. However, "5-limit" tuning presents its own problems... http://en.wikipedia.org/wiki/Five-limit_tuning He is correct (largely) on tritone substitutes and how they work. His "postulate 3" is misguided. Lydian dominant chords are 7#11s, not 7b5s. The distinction is important, because the lyd dom scale has a perfect 5th - therefore "b5" in the symbols is misleading. This matters when we consider tritone subs in practice. The lyd dom bII7 chord is not a sub for another lyd dom chord. It's a sub for an altered dominant. (Db7#11 in key of C - or C minor - is replacing G7alt: G7 with altered 5th and 9th.) His "postulate 3" should really be about wholetone chords: these are exact subs. Any 7b5 chord is the exact same notes as its tritone sub; but this implies wholetone scale, not lydian dominant. Nevertheless, he is right about lydian dominant being the best scale for a bII7 chord. (He's also right about underlying "scalar note groups" - I think he means "scales" - a scale usually covers a group of chords, or two at least; don't look for a different scale on any single chord unless the chord tones force you to.) His stuff on dim7s is also mostly good. He's not quite right that the chord itself is synthetic - it derives from the 7th degree of harmonic minor, a scale that existed way before 12-TET. Although I guess we can call harmonic minor itself "synthetic", as it's an artificial alteration of natural minor. The diminished scale, however - and the 4-way symmetry of modern dim7s - is synthetic, and dependent on 12-TET. His "Postulate 5", therefore, is good. I'll get back to you on the rest... but it may as well be
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